Environmental Impacts of the Future German Energy System from Integrated Energy Systems Optimization and Life Cycle Assessment

Abstract

Climate change mitigation requires a fundamental transition of our energy systems to reduce greenhouse gas (GHG) emissions. At the same time, ambitions to reduce GHG emissions should not shift burdens to other environmental impacts. Environmental impacts of technologies can be evaluated holistically using Life Cycle Assessment (LCA). Classical LCA is static and relies on historic process data. In contrast, dynamic LCA incorporates future changes in production processes and therefore allows for a consistent assessment of future environmental impacts. In this work, we develop a dynamic LCA model for the German energy transition. For this purpose, we combine LCA with energy systems optimization. We model the German electricity, heat, and transport sectors. For a given GHG target, the model designs the cost-optimal transition of the energy system. Environmental impacts are evaluated using dynamic LCA based on global energy scenarios. Compared to static LCA, dynamic LCA shows a 75 % higher impact in agricultural land occupation and smaller impacts in 15 out of 18 impact categories, demonstrating the need for the consistent assessment by dynamic LCA.